This application claims the priority of German application 19933678.4, filed Jul. 17, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an adjusting arrangement for a steering column tube of a steering system of a motor vehicle, having a swivellably disposed clamping lever which, in a released position, unblocks or, in a locked position, blocks a longitudinal or vertical displaceability of the steering column tube. The arrangement also includes an actuating device for the manual releasing or locking of the clamping lever, which actuating device has a grip arrangement which, in a vehicle-fixed mounted condition, is accessible from a driver seat position.
An adjusting arrangement for a steering column tube of a steering system of a passenger car is generally known. In order to be able to change a steering wheel of a driver position of the passenger car in its height as well as in its depth relative to a dashboard of the vehicle interior and relative to the driver""s sitting position, the steering column tube of the steering system is disposed in a vehicle-fixed manner by means of the adjusting arrangement. The adjusting arrangement has a clamping bolt which penetrates lamellar bundles on both sides of the steering column tube which are alternatingly provided with oblong holes extending in the longitudinal or vertical direction. On the clamping bolt penetrating the oblong holes, a clamping mechanism is arranged which, as a result of swivelling movements of the clamping bolt about its longitudinal axis, presses the lamellar bundles against one another or releases them. By means of the clamping mechanism, the flexible lamellae are pressed against the lateral fixed lamella which itself is supported on the stationary console. For swivelling the clamping bolt, a clamping lever is fixed on one end and is connected with a manual actuating device. The manual actuating device is accessible from the driver position, so that, as a result of a manual operation of the actuating device by the driver, the clamping lever can be released. Subsequently the steering wheel, including the steering column tube, can be adjusted into the desired position and then the clamping lever can be locked again.
It is an object of the invention to provide an adjusting arrangement of the initially mentioned type which ensures a simple, secure and comfortable operation.
This object is achieved in that a guide rail arrangement is arranged on the steering column tube so that it is aligned in the longitudinal direction of the steering column tube. On the guide rail arrangement, an adjusting slide block is slidable held and can be moved by the grip arrangement and which is connected with the clamping lever. Because the adjusting slide block is held on the guide rail arrangement which is fixed to the steering column tube, all forces occurring during the releasing or locking of the clamping lever, as well as during the adjustment of the steering column tube, are absorbed in the steering column tube, so that a constant, easy-motion and secure releasing and locking function of the clamping lever is provided. The grip arrangement, which can be operated from the driver position, can be easily and comfortably operated because it provides for the linear adjustment of the adjusting slide block.
In an embodiment of the invention, the guiding of the adjusting slide block on the guide rail arrangement, the swivel bearing of the clamping lever and a bearing of the grip arrangement are coordinated with respect to their guiding and bearing friction forces so that, during a longitudinal adjustment of the steering column tube, the steering-column-tube-fixed guide rail arrangement can be displaced with respect to the adjusting slide block held stationary by the clamping lever and the grip arrangement. As a result, during a longitudinal adjustment of the steering column tube, the grip arrangement remains stationary, so that, after the desired adjusting of the steering wheel and of the steering column tube, the driver finds the grip arrangement in the same position in which he had released it.
As a further development of the invention, the adjusting slide block is connected with the clamping lever by means of a coupling unit which compensates the translational mobility of the adjusting slide block with respect to the rotary mobility of the clamping lever. The coupling unit preferably has a guide bolt which is positioned in an oblong hole of the clamping lever. The oblong hole of the clamping lever has a dimensioned length such that the adjusting slide block, connected at least essentially rigidly with the guide bolt, can carry out its displacement movements between the end positions without the occurrence of distortions relative to the clamping lever.
In another embodiment of the invention, a tolerance compensation unit is integrated in the connection between the adjusting slide block and the clamping lever or the adjusting slide block and the grip arrangement. As a result, it is also ensured that mounting and manufacturing tolerances of the individual components do not impair the secure and easy-motion operation of the adjusting arrangement. In addition, the grip arrangement, which is accessible from the driver position, is always in the same inoperative position irrespective of the existing tolerances.
In another embodiment of the invention, the tolerance compensation unit is designed as a setting mechanism provided between the clamping lever and the adjusting slide block. As a result, it is possible to carry out a precise setting of the adjusting device irrespective of the existing tolerances.
In another embodiment of the invention, the setting mechanism, on the one hand, has a setting rod provided with teeth and, on the other hand, has a stop slide which can be displaced on the setting rod and has a locking member provided with corresponding teeth, which locking member can be manually changed into a released position and is spring-loaded such that it can automatically be restored into its locking position. This ensures a particularly simple setting of the adjusting arrangement.
The object according to the invention is also achieved in that the grip arrangement is displaceably disposed by means of a bearing in a vehicle-fixed steering column tube collar, which bearing has bearing elements which have such a play that the grip arrangement can carry out compensation movements about at least one axis extending transversely to the sliding direction. This ensures an easy-motion and a functionally secure operation of the grip arrangement. Deformations between the bearing in the steering column tube collar and the grip arrangement are avoided so that a low-noise operation of the grip arrangement is permitted. The essentially translational displacement movement of the grip arrangement provides an ergonomically favorable operation by the driver of the motor vehicle.
In another embodiment of the invention, the grip arrangement has an elongated grip arm which is coupled at one end to the adjusting slide block and, at the other end, has a grip element which is accessible from the driver seat position. The gripping arm is preferably made of a plastic material.
In another embodiment of the invention, the coupling of the gripping arm to the adjusting slide block is designed as a releasable locking mechanism. This creates a secure linking of the grip arrangement to the adjusting slide block which prevents an unintentional detaching of the gripping arm from the adjusting slide block.
In another embodiment of the invention, the gripping arm extends radially through a central opening of a bearing roller serving as a bearing element, which bearing roller is rotatably disposed about a horizontal axis of rotation extending transversely to the sliding direction of the gripping arm. In another embodiment, the recess of the bearing roller through which the gripping arm protrudes is larger in its width as well as in its height than the outer dimensions of the gripping arm. As a result, the compensating play is created for the gripping arm which permits an easy-motion and functionally secure actuating of the grip arrangement by means of the gripping element.
In another embodiment of the invention, spring elements are integrated in the bearing roller, which spring elements hold the gripping arm under prestress in a central guiding position. This embodiment avoids or at least reduces a rattling or any other generating of noise.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.